Having been one, and having argued with several, it generally means:
* Looking at how JavaScript started vs. where it is now.
* Complaining about the ways that the backward compatibility requirements of the language can lead to obscure bugs, e.g., auto-coercion on "==" comparisons can end up with surprising and sometimes bug-causing results
and, importantly
* Ignoring all of the best-practice advice to use linters (eslint, tslint) that, in a deterministic manner, prevent you from writing code that contains any of the above bugs.
TypeScript also solves 95% of the major JavaScript complaints.
>There's a lot more in the world than websites and phone apps that need code to run.
and
>I just think it's a bit hyperbolic to call javascript the most important thing happening in software engineering right now when we're solving much bigger global problems than that right now with technology.
If you count all of the code to run apps, servers, and web clients, I think you do hit the majority of code out there, at least if you're counting the number of developers working on it. I think you would hit a majority just with web client side. It seems like everyone and their sister does web development. With all three domains it seems trivial to hit 50%, and I think 80% is still a reasonable estimate. A quick search finds no statistics on this, though. :|
Whether there are "bigger global problems" that are being solved elsewhere isn't really relevant. It's entirely reasonable to say that something is highly important to "software engineering" if it has relevance to more than 50% of software engineers.